/**
 * Author  zxy
 * Date  2023/8/12 16:23
 */

import java.util.Scanner;
import java.util.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Question1 {

    static Set<Long> list = new HashSet<>();

    public static boolean func (long x, long y) {

        if (list.contains(x) && list.contains(y)) {
            list.add(x * y);
            return true;
        }

        long temp = y / x;
        if (temp * x == y) {
            if (list.contains(temp) || isNum(temp)) {
                return true;
            }
        }

        long mul = x * y;

        if (list.contains(mul)) {
            return true;
        }

        return isNum(mul);
    }

    static public boolean isNum (long x) {
        long left = (long)Math.sqrt(x);
        long mul = left * left;

        if (mul == x) {
            list.add(mul);
            return true;
        }
        return false;
    }

    public static void main(String[] args) {
        list.add((long)1);

        Scanner in = new Scanner(System.in);

        int n = in.nextInt();
        int ret = n;

        for (long i = 2; i <= n; i++) {
            if (isNum(i)) {
                list.add(i);
            }
        }

        for (long i = 1; i <= n; i++) {
            for (long j = i + 1; j <= n; j++) {
                if (func(i, j)) {
                    ret += 2;
                }
            }
        }

        System.out.println(ret);
    }
}